1. Field of the Invention
The invention concerns a process for checking a laser weld seam.
2. Related Art of the Invention
When laser beam welding one or more work pieces faults may occur, which lead to unacceptable losses in quality. For quality assurance, both subjective visual inspections as well as automated checks of the seam are the norm.
In the automated processes the work site is conventionally monitored during welding using point or surface detectors (cameras). This type of process can not detect faults which do not occur until after the actual interaction of laser beam and work piece, in particular, solidification phenomena. Beyond this, certain irregularities relevant to quality are not recognized, since relevant process signals are overridden by stronger signals of the process illumination with no information value.
This problem is partially compensated for by a process according to DE 43 21 463 C2. There the melt pool or melt flow side of the seam is monitored by a following IR-detector, so that the overriding of the quality-relevant signals by the interfering signals of the process light are reduced, however not excluded.